Structures made from portland cement concrete, especially bridge decks, prematurely deteriorate due to wear from exposure to traffic, severe weather conditions and improper application of the concrete or errors in engineering. These structures develop cracks that compromise the integrity of the concrete and expose the reinforcing bars to corrosive elements. Additionally, after a few freeze/thaw cycles, cracks develop into holes that require repair. Many strategies have been employed in an attempt to protect and repair these structures, including providing a protective latex modified concrete overlay, epoxy coating the reinforcing steel, providing an asphaltic concrete/membrane system and feeding a low viscosity, low modulus polymer into the cracks in concrete decks.
U.S. Pat. Nos. 4,197,225 and 4,263,372, both to Emmons et al. describe polymer concrete compositions and coating compositions, respectively. These composition each contain dicyclopentenyl methacrylate or acrylate together with another non-volatile monomer, that is either an acrylate or ethacrylate, and a metal drier. The '372 patent, which claims only methods of using polymer containing coating compositions, is specifically limited to C.sub.12 to C.sub.30 alkyl and alkenyl acrylates and methacrylates as the comonomer. The '225 patent, which claims only polymer concrete compositions and products obtained from these compositions, is limited in scope of the comonomer to non-volatile monomers such as higher alkyl or alkenyl acrylates or methacrylates.
U.S. Pat. No. 4,460,625 to Emmons et al. discloses a polymer impregnate composition comprising a monomer system containing dicyclopentenyloxyalkyl or dicyclopentenyloxyalkyl ester of methacrylic acid or acrylic acid, at least one hydroxy alkyl methacrylate and a polymerization catalyst.
U.S. Pat. No. 2,462,400 to Hoover et al. discloses a coating composition prepared in solvent that comprises 20 to 50% dicyclopentenyl methacrylate and 80 to 50% of an ester of methacrylate with a saturated aliphatic monohydric alcohol having from 8 to 18 carbon atoms. This patent teaches at column 3, lines 62 to 75 that the recited relative monomer contents of the composition are essential to achieve the desired flexibility and resistance of the film to marking. The relative ratios of monomers in Example II and the indicated substitution ratios at column 3, lines 45 to 53 indicate that the shorter the alkyl chain in the alkyl portion of the methacrylate comonomer, the more total comonomer is required.
U.S. Pat. No. 2,414,089 to Bruson discloses the incorporation of dicyclopentenyl methacrylate in paints, varnishes and similar coatings, where the compounds polymerize by absorbing oxygen from the air to form tough, solvent insoluble compositions.
U.S. Pat. No. 3,644,316 to Marx et al. discloses air-drying coating agents and impregnants which contain (a) an ester of an olefinically unsaturated caroxylic acid with the acetoacetic monoester of an at least dihydric alcohol; (b) at least one other polymerizable ethylenically unsaturated compound and (c) a conventional polymerization initiator.
Previous coating materials for porous surfaces using dicyclopentenyl acrylate or similar compounds utilized comonomers in an attempt to flexibilize the coating without regard to tensile strength. These coatings, including those of the Hoover '400 and Emmons patents cited earlier, indicate that the carbon content of the acrylate or methacrylate comonomer in the alcohol portion should be greater than about 10, and the comonomer should be present as a preponderance of the monomer mixture. These coating compositions for use with concrete were unsatisfactory because either at least one of the constituent monomers was too volatile and was lost to the air, the coating was not sufficiently flexible to prevent further cracking of the concrete and/or the polymer coating composition lacked the ability to penetrate the substrate in an amount sufficient to effectively repair cracks.